In my experience Delta 400 looks grainier than other T-grain 400 speed films. Embrace the grain. It is a lovely image.
I've never had this issue with it. Usually my Delta 400 in 120 looks more like a 100 speed film in 35mm for me. This image looks more like what my Delta 3200 looks like in 120. I must have done something during the developing process to cause this. I'm going to photograph her again in the future so I'll give it another shot.